1. Field of the Invention
The present invention relates to a cooling device for cooling an interior of a closed box member for accommodating a heat generating member such as an electronic component part.
2. Description of Related Art
An electronic component parts having a semiconductor therein or the like may be accommodated in a closed box, e.g., a closed housing, in order to prevent a malfunction caused by deposition of dusts, trash and moisture or the like. In this case, since the electronic component parts is a heat generating member, it is necessary to cool an interior of the housing; however, it is not possible to blow directly outside air into the housing to cool the heat generating member. Therefore, it has been proposed to provide a cooling device employing a heat exchanger composed of a heat pipe or the like, which performs a heat exchange between air of high-temperature within the housing and air (outside air) of low temperature to cool an interior of the housing.
The above-described cooling device is provided with an inside blower for blowing air of high temperature within the housing against a heat-receiving portion of the heat exchanger. The cooling device is also provided with an outside air blower for blowing outside air against a radiating portion of the heat exchanger as well as with a temperature sensor for sensing a temperature of air of high temperature. Each of the inside air blower and outside air blower is composed of a fan and a motor.
In the above-described cooling device, normally, each motor of the inside blower and the outside blower is continuously electrified and operated to cool an interior of the housing. Further, when a temperature of the outside air is decreased and the temperature detected by the temperature sensor is equal to or less than 0.degree. C., the motor of the outside air blower is turned off and stopped. In this way, the interior of the housing is cooled so that the temperature in the housing is maintained at approximately 0 to 65.degree. C., for example.
However, according to the above-described cooling device, since each motor of the inside air blower and the outside air blower is continuously electrified and operated, there occurs a problem in that the consumed electric power and noise increases greatly; and therefore, it is necessary to improve the cooling device in view of the energy saving.